某矿区土壤重金属分布特征及来源解析

为探究赣南某矿区土壤重金属污染状况及来源,以该矿区内40个土壤样品为研究对象,分析了土壤中Cu、Pb、Zn、Cr、Ni、Cd、As和Hg等8种重金属元素的含量,并采用频率直方图、相关性分析、主成分分析等多种统计方法探究了土壤重金属含量的分布特征及来源。研究结果表明:(1)研究区8种重金属中有7种不同程度地超过了江西省土壤重金属元素背景值;(2)Pb、Zn、As和Hg的含量接近正态分布,而Cu、Cr、Ni和Cd的含量则呈现出右偏分布的趋势,这可能与研究区矿山开采活动及土地利用类型等因素有关;(3)矿区土壤重金属相关性分析表明,Cu、Cr、Ni的同源性较高,可能具有相同的污染源,而Pb、Zn、Cd等元素与Cu、Cr、Ni相比,其来源可能存在一定的差异;(4)主成分分析结果显示,矿区内土壤中8种重金属元素含量可以由2个主成分来解释,所代表的实际意义按贡献率排序分别是成土母质和人为采矿活动;(5)矿区内土壤重金属污染物主要为Pb、Zn、Cd,人为采矿活动是这三种重金属污染的主要来源。

Identification of Heavy Metal Distribution and Sources in Soil from a Mining Area

To explore the conditions of heavy metal pollution (incl. Cu, Pb, Zn, Cr, Ni, Cd, As, and Hg) and their sources in soils from a mining area in southern Jiangxi, a total of 40 soil samples were collected. Distribution characteristics and pollution sources of heavy metals were analyzed by a series of statistical methods, including frequency histogram, correlation, and principal component analyses. Our results suggest that: (1) Seven (out of eight) heavy metals measured in the soil samples exceed the Jiangxi background contents in varying degrees; (2) Contents of Pb, Zn, As and Hg in the soil exhibit normal distributions, while Cu, Cr, Ni and Cd contents show right inclining distributions. This may due to the varying extent of mining activities and different types of local land use; (3) Positive correlations among the soil Cu, Cr, and Ni contents suggest that they may have similar pollution sources, while the sources of Pb, Zn, and Cd may be different from those of Cu, Cr and Ni; (4) Principal component analysis suggests that contents of the eight heavy metals measured in soils may be the combined effect of two principal components, i.e., soil parent materials and mining activities; (5) Pb, Zn and Cd are the primary pollutions of the soil samples, and were mainly sourced from local mining activities.